Grinding mill



Nov. 6, 1928.

c. E. NEEDHAM GRINDING MILL Filed Feb. 5, 1925 6 vSheets-Sheet l m Ww.N3 m uw M Mmm b wha, S. S- A` w town.

www@ uw, N m. N @x n NN N Nav, 6, 1928., 1,690,125 'E C. E. NEEDHAMGRINDING MILL Filed Feb. 5, 1925 6 Sheets-Sheet 3 INVENTOR Nov. 6, 1928.1,690,125

` c. E. NEEDHAM GRINDING MILL Filed Feb.`3, 1925 6 Sheets-.Sheet 4 Z55lNvENToR CAM mkm.

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Nov. 6, 1928. 1,690,125

C. E. NEEDHAM GRINDING MILL Filed Feb. 5, 192s e sheets-snm 5 INVENTORRNEY C. E. NEEDHAM GRINDING MILL Nov. 6, 1928.

6 Sheets-Sheet 6 Patented Nov, 6, 1928.

A y y 1,690,125 UNITED STATES PATENT OFFICE.

CHARLES NEEDH'AH, -0F ALLENTOWN, PENNSYLVANIA, ASSIGNOB T) BETLEHEIFOUNDRY MACHINE COMPANY, A CORPQBATION I' PENNSYLVANIA.

GBINDING MILL. -v

Application mea February a. 1925. sensi no. 6,520.

This invention relates to grinding or pulverizing mills and particularlyto that type of mill wherein the material to be ground is crushedby'rolls which are forced outwardly 6 by centrifugal force against theinner face of an annular-die. In the embodiment of my invention hereindisclosed, the crushing rolls are hung from an overhead support which isrotated by a vertical shaft driven by overhead gearing. The movableparts of the mill are carried by `a frame which comprises two oppositelylocated interchangeable uprights or legs mounted on the base of the milland connected at their tops by an overhead structure which forms abearing-and support for the vertical shaft and for the operatinggearingk for said shaft. i

One of the objects of my invention is to improve the construction ofthis supporting frame in such a manner that it is better able towithstand the strains incident to the operation of the mill. It has beencustomary herj tofore, in order to prevent vibration or lateral strainson the vertical shaft, to employ a hol- 25 low or quill shaft which isheld against lateral displacement by a fixed member that eX- tendsupwardly into and bears against the inner surface of the hollow shaft.This construction is complicated and 'expensive and the shaft, by beingmade hollow. is considerably weakened. By forming the overhead supportfor the shaft of extremely rigid and strong construction and byemploying a lower bearing supported from the hollow of the grindingchamber, I am able to employ a solid shaft which will be securely heldagainst any injurious vibration.

A further object of my invention is to provide an improved supportingframe which may be economically manufactured, readily assembled andadjusted to proper assembled relation. A furtherl object is to provide asupporting frame which can be made in standard parts ready for shipmentto place of installation and which can be then assembled without furthermachining or otherwise altering the form of the parts.

The grinding mill herein disclosed is adapted to be operated by a motorlocated at the side of the mill, this motor being connected to adrivingshaft mounted inthe overhead supporting frame. For convenience ofarrangement, it is sonietimes desirable to mount the driving shaft/ atone side of the mill and sometimes at the opposite side. In accordancewith my invention, the mill actuating gearing and its supportingstructure is so designed that the same parts may be assembleddifferently and the actuating shaft positioned to extend in onedirection or another as desired so that the driving motor may be locatedupon one or the other side of the mill.

A further obj ect of the invention is to provide an improved means forlubricating the mill actuating gearing and also to provide an improvedmeans for lubricating the crushing roll bearings.

In mills of the type described, it is customary to employ plows whichmove in the grinding chamber beneath the grinding rolls and serve tostir up the material to be ground and force it into the path ofthegrinding rolls. A further object of my invention is to provide animproved and simplified supporting structure for these plows.-

A further object is to provide an improved mounting for the spindleswhich carry the grinding rolls.

A further object is to provide an im-v proved means for supporting thecrushing rolls whereb the rolls may be removed and replaced wit outdisturbing the bearings on which they are rotatably mounted.

.While I have described various features .of my invention as applicableto a grinding mill, it will be obvious that certain of these featuresare of more general application.

Numerous other objects and advantages will appear from the followingdescription taken in connection with the 'accompanying drawing, whereinFig. 1 is a front elevation, partly 1n section, of a grinding mill,showing one embodiment of my invention.

Fig. 2 is a vertical section, partly in elevation and partly brokenaway.

Fig. 3 is a side elevation of one of the cast metal uprights or legsforming a portion of the supporting frame for the'moving parts of themill.

Fig. 4 is a section taken on the line 4--4 arrows.

Fig. 5 is a section taken on the line 5 5 of Fig. 2.

Fig. 6 is a vertical section, partly in elevation, of a grinding rolland its spindle mountmg.

Fig. 7 is a horizontal section taken on the of Fig. 8, looking in thedirection of the of the arrows.

Fi 8 is a bottom elevation of a grinding roll s owing the means forsecuring the same to its support.

Fig. 9 is a section taken on the line 9-9 of Fig. 8, looking in thedirection of the arrows.

Fig. 10 is a view similar to Fig. 1, but showing a modified form ofoverhead supporting structure.

Fig. 11 is a top plan of a portion of the housing and supportingstructure for the mill actuating gearing as employed in the form ofinvention shown in Fig. 10.

Fig. 12 is a top plan of the supporting structure for the Verticalactuating shaft for the form of invention shown in Fig. 10.

Fig. 13 is a side elevation of the structure shown in Fig. 12.

Referring more particularly to Fig. 2 of the drawing, the grindingchamber 2O is formed by a lower base casting 21, upper annular member 23which is supported from the base 21 and connecting screen 24, thegeneral arrangement of these parts being such as is customarily employedin grinding mills of the type disclosed. Suitably supported inside thebase 21 is a fixed annular die 25 which is adapted to be engaged bygrinding rolls 27 of which there are a p urality equally spaced.Grinding rolls 27 are rotatably mounted on spindles 28 which are swungin bearings 29 mounted upon a rotatable plate 30 which is carried by avertical actuating shaft, 31. The plate 30 is formed with openings 40adapted to receive material to be ground from a hopper 41 and deliverthe same to the grinding chamber in front of the grinding rolls 27through chutes 43. The shaft 31 is adapted to be rotated by gearing 34which receives power from an outwardly extending shaft 22 connected to amotor not shown. Shafts 31 and 22 and gearing 34 are housed andsupported in a frame 36 which comprises two uprights or legs 37 and anoverhead connecting structure 38. A

Referring more particularly to Figs. 3 and 4, each o f the uprights 37is formed of a casting havmg top and bottom portions and 5 1 and acenter and two side connecting portions 53 and 54 of the form shown.Strengthenmg ribs or flanges 55 extend upwardly from the bottom of theupright and are connected at the top and bottom by flanges 56 and 57.Each of the uprights 37 is rigidly mounted on and connected to the base21` there being provided for this purpose segmental flanges or ribs 58,preferably formed integral with the base 21. The outer surface of eachof the flanges 58 and the inner surface of the bottom 51 of the uprights37 are turned to cylindrical form so that the bottom 51 of the uprightswill fit tightly against the flange 58. Securing bolts 60 pass throughthe bottom of the uprights 37 and through the flange 58 and also throughthe flange 57 and into the base 21 for the purpose of securing theseparts together. The upper face of the top portion 50 of the uprights ismachined and the inner face 63 of each top portion 50 is machined sothat these surfaces form a portion of a cylinder having as its axis theaxis of the vertical driving shaft 31. The overhead connecting structure38 comprises a beam 65 which is provided near its ends with dependingflanges 66. The outer faces of the flanges 66 are turned to cylindricalform so as lto t the inner faces 63 at the top of the uprights 37 andthe lower face of each end of the beam 65 beyond the flanges 66 ismachined so as to fit the upper face of the uprights 37. Bol-ts 68 whichpass through the upper portion of the uprights 37 and through the beamand flanges 66 serve to secure the beam to the uprights 37.

In constructions of this character heretofore employed. it has been thepractice to form each of the uprights 37 of a plurality of fabricatedrolled steel members which were secured in an assembled relation whenthe mill was installed. Considerable dilliculty was experienced infitting the fabricated rolled steel members or other parts of theuprights together and a considerable amount of machining, cutting anddrilling was necessary in the installing process. By forming theuprights 37 of a single casting and machining the parts in the mannerdescribed. I provide a unitary construction and there is thus nonecessity of further machining or altering the form of the parts whenthe mill is installed. By making the legs. bases and beams of standardsizes and form. the substitution of parts for those which are worn orinjured is greatly facilitated. By joining the beam 65 with the legs 37along the flat top surface of the legs and the cylindrical surface 63.it is possible to mount the beam 65 with the driving shaft 22 extendingtoward the left as shown .in Fig. 1. or if dcsired. the beam and partscarried thereby may be secured to the uprights with the shaft extendingtoward the right. that is, the beam and its connected parts turnedthrough an angle of 180o and the end of the beam which is now connectedto the left hand upright would be connected to the right hand nprightand vice versa. In this manner the position of the driving motorrelative to the feeding mechanism which supplies thi` hopper 41 may bealtered so that the feeding mechanism is positioned at the right or atthe left of the driving means.

The beam 65 is formed with a central portion 71 having an opening forthe reception of the shaft 31. Keyed to the upper end of the shaft 31 isa bevel gear 73 which is supported upon a thrust loller bearing 75contained in au enlargement 76 of the central portion 71 of the. beam65. The extreme upper end of the shaft 3l is `screw threaded at Utl lun

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78 and receives a nut 79 which bears on the upper end of the hub of'gear 73. From this construction it will be seen that the weight of theshaft 31 is sustained by the bearing 75 through the hub 80 of the gear73. The enlarged portion 76 is formed with an outwardly extending fiange82 which' carries the gear casing or pan 83 formed of a lower portion 85and an upper portion or top 86 bolted to the lower portion. The beam 65at the left of its central portion, as shown in Fig. 1. is formed with arecess which extends along the length of the beam which recess is formedwith a central depression 91.

The actuating shaft 22 extends into the recess 90 and is journaled in aroller bearing 95 located at the inner side of the depression 91 and aroller bearing 96 at the outer side of the depression 91. A bevel pinion98 is keyed to the shaft 22 between the bearings 95 and 96 vand isadapted to mesh with and operate the bevel gear 73. Between the bearing96 end the pinion 98 is a plate 100 which isrigidly secured in therecess 90 and between the plate 100 and the pinion 98 is a thrustbearing 101. The plate 100 serves the purpose oi receiving the thrust ofthe thrust bearing 101 and also acts as a partition to prevent oil inthe bearing 96 from flowing directly into the depression 91 of therecess 90 in a manner more fully to be describedhereatter. The top oithe plate 100 is formed with an opening or channel 103(` which forms acommunication between the bearing 96 and the space surrounding thepinion 98. To the rear of the bearing 96, the recess 90 forms a chamber105 which chamber is in communication with the depression 91 by means ofa pasgage 106. Oil in the chamber 105 is prevented from flowingoutwardly along the shaft 22 by means of a labyrinth seal 107 yand apacking gland 108. The upper inner wail'of the 'casing or pan 83immediately above the pinion 98 is inclined asshown in Fig. l andterminates at its lower end at a pointV 110 which lies imme diatelyabove the opening 103.

In practice. oil is introduced through an opening 112 in the top of thegear housing above. bearing 96 and flows downwardly intothe depression91 where it assumes a level indicated roughly by a dotted line inFig. 1. As the pinion 98 is rotated, a part of this oil will be carriedor thrown upward against the bevel gear 73 and against the top of thepan 83. A part of this oil will fiow down the inclined inner face of thepan to the point 110 and will then drop oli into the opening 103 fromwhence it will ilow to the bearing 96 and lubricete the same. This oilwill return to the depression or oil sump 91 through the pasfage 106which leads from the chamber 105 to the sump. In this manner. it will beseen that a constant circulation of oil is main tained to and from thebearing 96 and at the same timethe natural level of theoil in the recess90 will be sufficiently low so that there will be no tendency of the oilto iow out through the gland 108. There is no opening through which oilin the recess90 at the rear of bearing 95 may escape and this bearingwhich receives a suliicient amount of oil from the splash of the pinion98 will be well lubricated. For the purpose of directing a portion ofthe oil splashed up by the pinion 98 to the bearing 95, a batlie 99 maybe provided. located abovethe bearing 95.

In the form of invention disclosed, I have shown a split bearing member115 secured by bolts on lthe base 21 in which the lower end of theshat't 31 rotates. The bearing 115 acts as bracing means for the lowerend of the shaft 31 but does not sustain the Weight of the shaft, thisweight being sustained entirely by the upper bearing 75.

The plate 30 is circular in form and extends outwardly to within a shortdistance of the annular member 23 so as to prevent dust from thegrinding chamber 20 getting into the bearings above the plate 30. Theplate 30 is provided with radially extending openings or slots 116through which extend the roll carrying spindles 28. The up-per portionof each of the spindles 28 is tapered at 117 and is adapted to he firmlysecured within a tapered opening 117 in a rocker head 118 by means ol anut 119 which engages the screw threaded end 120 o't thespindle 28. Therocker head 118 has, preferably east integral therewith, a portion 122which forms at its outer ends the trunnions 123. 'I'runnions 123 aresupported in the bearings 29, bolted to the plate 30. one at each sideof the slot 116. The trunnions 123 are preferably formed with removablesteel facings or sleeves 126 which bear on the brass linings 127 of thebearings 29. By forming the trunniens 123 integral with the rocker head.an exceedingly strong and simple construct-ion is provided and little orno ditiieulty is experienced in making and maintaining the parts tight.Plates 121 and 124'a-re secured to the top of the supporting plate. 30and serve as closures for the portions of the openings 116 which are notclosed by the rocker head 118.

Rotatably supported on the spindle 28 is a hollow mem er 130 whichcomprises a member 131 carrying the crushing roll 27 and a sleeve orannular member 132 which is rigidly secured to the roll-supportingmember 131 by bolts 134. The spindle 28 is formed with an enlargement orflange 135, ormin g a shoulder which l. arries the weight of thecrushing roll and member 130 through a roller or other thrust bearing137. Between the sides of the lower end of the spindle 28 andthe sideinner wall ot' the roll-supporting member 131 are roller bearings 141.Fixed to the interior of the member 131 is a bearing plate 14:4 which isadapted to rotate against a thust button secured to the lower end of thespindle 28. The inner wall of the sleeve member 132 above the thrustbearing 137 is tapered upwardly to a point 147 close to the spindle 28so as to form an oil chamber 148. Above the point 147 the interior ofthe sleeve member 132 expands to form an oil chamber 150. In the upperportion of the chamber 150 and between the sleeve member 132 and thespindle 28 is located the. roller bearing 151. Seated in the chamber 150above the bearing 151 and secured to the sleeve member 132 is an annularmember 153 which is spa.l ed from the spindle 28 at its lower end, butis in contact therewith at its upper portion. The upper ends of theannular member 153 and the sleeve member 132 and the lower face oftherocker head 118 form a labyrinth to prevent the escape of oiloutwardly from the ch'amber 150. Oil is supplied to the spindle bearingsthrough a vertical passage 162- which is normally closed at its top by'a plug 163 and communi cates at its lower end through an opening 164 inthe thrust button 145 to the space between the thrust button and thelate 144.

The oil which is supplied to the passage 162 passes between the thrustbutton 145 and the plate 144, thence upwardly through the bearing 141`around the outer edge of the enlargement 135 of the spindle 28, throughthe thrust bearing 137 upward through tapered chamber 148 into thechamber 150 where it comes in contact with and lubricates the bearing151. By forming the chamber 148 with an upward taper as shown, or with acontract ed upper portion, oil introduced into the passage 162 remainsin contact with the bearings 141 and 137 during operation of themachine. If the outer wall of the chamber 148 were vertical instead ofinclined as shown, the eentrifugal force due to the rotation of themember 130 would cause the oil in the, chamber 148 to rise along itsouter wall with the result that it would be thrown out at the top of themember 132 and the lower spindle bearings would quickly become dry. Byforming the chambers 148 and 150 in the form shown, the oil is merelyforced against the outer wall of the chamber and the tendency to rise inand fiow out of the chambers, due to centrifugal force, is counteracted.It will of course be understood that sufficient oil is introduced intothe passage 162 to cause the oil to rise into the chamber 150.

The roll 27 is formed with a tapered opening adapted to receive thetapered portion 171 of the member 131. The tapered portion of 171carries an outwardly projecting pin which is seated in a slot 176 in theinner portion of roll 27 to prevent rotation of the roll 27 on themember 131. The roll-carrying member 131 is screw threaded at 173 at itslower end and is adapted to receivea nut 174. The nut 174 is providedwith a plurality of openings 178, the lower ation of the mill.

portions of which are circular in cross section and the u pper portionssquare in cross section and tapered as shown in Figs. 8 and 9. Each ofthese openings is adapted to receive a jack screw 180. The jack screw isformed at its outer end with a squared head 181, an intermediate screwthreaded portion 182 and at its inner end with a flanged head 183adapted to bear against the roll 27. Between the threaded portion 182 otthe jack screw and the tapered walls of the opening 178 is a splitlocking sleeve 135 which is screw threaded on its inner surface and hasan inclined outer surface adapted to en gage the tapered surface of theopening 182.

In order to secure the roller on the member 131, it is placed over andtapered portion 171 and the nut 174 screwed on by hand. The jack screws180 are then tightened in succession with the result that the pressureheads 183 force the roll 27 tightly against the outer tapered surface ofthe portion 171. The sleeve 185 by this operation is forced back intothe tapered recess thereby locking thc screw 180. In this manner, theroll 27 is securely fastened to the member 131 and there is practicallyno danger of the screws 180 or of the roll 27 working loose during theoper- It will be noted that the roll 27 is removable and may be renewedwithout disturbing or necessitating the renewal of its bearing support.When a roll be.- comes worn and requires replacement, it is generallymerely necessary to replace the roll itself as all other parts may beused with the new roll. The flanged head 183 is formed of largerdiameter than the opening in the sleeve 185 so that in case the screw180 should happen to become loose, there is no danger of its falling outof the opening 178.

The plate 30 is extended at the openings 40 to form tubular supportingportions 190 for the chutes 43, the chutes 43 being secured in thetubular portions by a bayonet joint indicated at 192 and by asemi-cylindrical strap 193 which is secured by bolts 194 to a shoulderwhich may be regarded as formed by cutting away a portion of the end ofthe extension 190. Plow bars 195 are secured to the extensions 190 bymeans of bolts 196 and straps 197 and are adapted to carry the plows 198which move through the mass of unground material lying at the bottoni ofthe grinding chamber and force the same upwardly into the path of thegrinding rolls 27.

In Figs. 1013 inclusive, I have shown a modified mounting for themovable parts` of the mill. Instead of mounting the vertical shaft 31and the gearing 34 on a single beam as is shown in Figs. 1 and 2, Iprovide one mounting for the shaft 31 and gear 73 and a separatemounting for the shaft 22, pinion 98 and the gear housing. For thispurpose, I provide two supporting members 200 and 201, each of which isadapted to be independlll) cntly supportedat its ends by the uprights37. vThe member 201 which forms the'gear housing, instead of beingbolted to an overheadv beam as shown at 82 in Fig. 1, is supporteddirectly on the uprights 37, being secured at one of the uprights at 203and on the other upright by means of a leg 204 which is carried by thepan 205'. The member 200 which forms the supporting beanrfor thevertical shaft 31 and the parts carried thereby' is formed at one endwith spaced projections 206, which are secured to one of the uprights 37and embrace the lower end o f the leg 204.4 At its opposite end, themember 200 is bifurcated to form arms 208 which surround the recessedportion 209 of the member 201 and terminate in supporting end portions210 Whichrest upon and are secured to the other upright 37. The members200 and 201 are separately and independently supported and may beadjusted in position relative to one another, as for example, byinserting shims between the tops ofthe uprights 37 and onel or other ofthe members. This is advantageous in frder to secure the proper meshingof the pinion. 98 with the gear 73. The meinbers 200 and 201 also havean advantage over the beam 65 as shown in Fig-1 in that they are ofsimpler 'and cheaper construction than the beam 65.

1. In acentrifugal grinding mill having a grinding chamber, a baseformed with an upstanding surface turned concentric with the verticalcentre axis of said grinding chamber, grinding rolls movable in saidchamber, a vertical shaft for moving said rolls, gearing for actuatingsaid shaft and a supporting frame comprising two uprights, each formedof a heavy casting mounted on said base, said castings expanding'perpherally to- Ward said base and being formed with turned surfacescomplementary to and fitting the turned surfaces on said base, saidcastings being formed with machined upper surfaces and an overheadcasting mounted on said uprights and having supporting bearings for saidshaft and gearing, and being formed with machined surfaces which it themachined surfaces of said uprights.-

2. In a centrifugal grinding mill having a grinding chamber, grindingrolls movable in said chamber, a vertical shaft for moving said rolls, abase casting formed on its upper face with ribs located at oppositesides of said grinding chamber, each of said ribs having anapproximately cylindrical side surface, two uprights supported on saidbase, each formed of a casting having an approximately cylindricalsurface adapted to fit. the surface of said ribs, and an overheadstructure secured to the top` of said uprights and forming a supportingbearing for said vertical shaft.

3. In a centrifugal grinding mill having a grinding chamber, grindingrolls movable and forming a supporting bearing for saidv vertical shaft.

4." In a centrifugal grinding mill having a grinding chamber, grindingrolls movable in saidy chamber, a vertical shaft for moving saidV rolls,a base casting, interchangeable uprights secured to said base onopposite sides of said grinding chamber, and an overhead structureforming a supporting bearing for said shaft, said structure beingsupporter onsaid uprights in one position and being adapted to besupported on said uprights in a reverse position.

5. In a centrifugal grinding mill having a y,grinding chamber, grindingrolls movable in said chamber, a vertical shaft for moving said rolls, abase casting, interchangeable uprights, each formed of a single casting,secured to said base on opposite sides of said grinding chamber, and anoverhead structure forming a supporting bearing for said shaft, saidstructure being supported on said uprights in one position and beingadapted when disconnected'from said uprights to be rotated `horizontallythrough 180 without removing said uprights, grinding rolls and verticalshaft and to be supported on said uprights in a reverse position.

6. In a centrifugalgrinding mill having a grinding chamber, grindingrolls movable in said chamber, a vertical shaft for moving said rolls,said shaft being adapted to sustain the weight of said rolls, a basecasting formed with ribs at opposite sides of said grinding chamber, twouprights each formed of a single heavy casting resting on said base andsecured to said ribs, said last named castings being formed with a fiattop and an approximately cylindrical upper side surface, and an overheadstructure on said uprights, said structure forming a supporting bearingfor said shaft and formed atits ends with flat and cylindrical surfacesadapted to iit and to be' secured to the fiat and cylindrical surfacesrespectively of said uprights, the parts being formed so that saidstructure may be reversed in position on said uprights.

7. In a grinding mill, a grinding chamber, feeding means at one side ofsaid chamber for delivering material thereto, grinding elements movablein said chamber, a vertical shaft for moving said elements, gearing foroperating said shaft, a base, uprights, each formed of a casting securedto said base, an overhead structure forming supporting bearings for saidshaft and gearing, an actuating shaft extending along said structure toa point at one side of said feeding means, said overhead structure beingcarried by said uprights and adapted to be secured thereto in a positionsuch that said actuating shaft lies at one side of said feeding means orin a position such that the said actuating shaft lies at the other sideof said feeding means. y

8. 'In a centrifugal grinding mill having a grinding chamber, grindincrolls movable in said chamber, a vertical shalft for moving said rolls,gearing for actuating said shaft, a base, uprights, each formed of acasting mounted on said base at opposite sides of said grinding chamber,an overhead beam supported on said uprights and forming a supportingbearing for said shaft and a housing for said gearing supported on saiduprights.

9. In a centrifugal grinding mill having a grindingchamber, grindingrolls movable in said chamber, a vertical shaft for moving said rolls,gearing for actuating said shaft, a base, uprights, each formed of acasting mounted on said base at opposite sides of said grinding chamber,an overhead beam supported on said uprights and forming a supportingbearing for said shaft and a housing for said gearing supported on saiduprights, said housing being separated from said beam.

10. In a centrifugal grinding mill having a grinding chamber, grindingrolls movable in said chamber, a vertical shaft for moving said rolls,gearing for actuating said shaft, a base, uprights, each formed of acasting mounted on said base at opposite sides of said grinding chamber,a housing for said gearing supported at its ends on said uprights, andabeam formed with bifurcated ends embracing the ends of said housing andsecured to said uprights.

11. In a centrifugal grinding mill having a grindingchamber, grindingrolls movable in said chamber, a vertical shaft for moving said rolls,gearing for actuating said shaft, a base, uprights, each formed of acasting mounted on -said base at opposite sides ol said grindingchamber,'a housing for said gearing supported at its ends on saiduprights, and a beam formed with bifurcated ends embracing the ends ofsaid housing and secured to said uprights, said beam and housing beingseparate and independently supported on said uprights.

12. In a centrifugal grinding mill,having a grinding chamber, grindingrolls movable in said chamber, a vertical shaft for moving said rolls,gearing for actuating said shaft, a base, supporting means mounted onsaid base, an overhead beam supported on said means and forming asupporting bearing for said shaft, and a housing for said gearingsupported on said means, said housing being separate from said beam.

13. In a centrifugal grinding mill having a grinding chamber, grindingrolls, movable in said chamber, a vertical shaft for movin f said rolls,a bevel gear on said shaft, a bevdl pinion meshing with said gear, alaterally extending shaft on which said inion is mounted, a base,uprights mounte on said base on opposite sides of said grinding chamber,a housing supported at its ends on said uprights and formed with arecessed portion adapted to enclose said pinion, and a beam supported onsaid uprights and formed with bifurcated ends embracing said recessedpor tions.

14. In a centrifugal grinding mill having a. grinding chamber, grindingrolls movable in said chamber, a vertical shaft for moving said rolls, abevel gear on said shaft, a bevel pinion meshing with said gear, alaterally extending shaft on which said pinion is mounted, a base,uprights mounted on said base on opposite sides of said grindingchamber, a housing supported at its ends on said uprights and formedwith a recessed portion adapted to enclose said pinion, bearings on saidhousing for said laterally extending shaft, said recessed portionforming an oil for lubricating said pinion and bearings, and a beammounted on said u rights independently of said housing and ormed with abifurcated end embracing said recessed portion.

15. In a centrifugal grinding mill having a grinding chamber, grindingrolls movable in said chamber, a vertical shaft for moving said rolls, abevel gear on said shaft, a bevel pinion meshing with said gear, alaterally extending shaft-on which said pinion is mounted, a gearhousing formed with an oil well in which said pinion rotates, bearingsin said housing for said laterally extending shaft, and means wherebythe rotation of said pinion supplies oil to said bearings.

16. In a centrifugal grinding mill having a chamber, grinding rollsmovable in said chamber, a vertical shaft for moving said rolls, a bevelgear on said shaft, a bevel pinion meshing with said gear, a laterallyex tending shaft on which said pinion is mounted, a gear housing formedwith a well adapted to contain oil in which said pinion dips, bearingsfor said laterally extending shaft in said housing above said well, andmeans whereby oil raised by the rotation of said pinion is supplied tosaid bearings.

17. In a centrifugal grinding mill having a grinding chamber, grindingrolls movable in said chamber, a .vertical shaft for moving said rolls,a bevel gear on said shaft, a bevel pinion meshing with said gear, alaterally extending shaft on which said pinion is mounted, a gearhousing formed with a well adapted to contain oil in which said piniondips, a bearing for said laterally extending shaft in said housing abovesaid Well, the top of said housing above said pinion being inclinedtowards said bearing so that oil raised by i rotation of said pinionwill be supplied .to said pinion below said gear and meshing therewith,a horizontal shaft upon which vsaid pinion is mounted, bearings for saidshaft on the outer side of said pinion, a gear housing formed with arecessed portion adapted to contain said' pinion and bearings, said re,-cessed port-ion being formed with a depression adapted to contain oil inwhich said pinion dips, a partition between said bearing and pinion andformed with an opening in its'upper portion, said housing being formedwith an inner passage extending beneath said bearing and partition andthe top of said housing above said pinion being inclined downwardltoward said opening whereby oil in said epression, by the rotation ofsaid pinion, is splashed up onto the inclined top of said housing, flowsdown into said opening to said bearing, thence through said bearing andsaid passageback' to said'depression.

19. In a grinding mill, movable grinding elements, a vertical shaft formoving said elements, a bevel gear on said shaft, a bevel pinion below'said gear and meshing therewith, a horizontal shaft upon which saidpinion is mounted, a bearing for said shaft, a gear housingformed with arecessed portion adapted to contain said pinion and bearing, saidrecessed portion being formed with a depression4 adapted to contain oilin which said pinion dips, a partition between said bearing and pinion,the top of said housing above said pinion being inclined outwardlyand-said parts being formed with upper and lower passages leading tosaid bearing whereby oil in said depression, by the rotation of saidpinion, is splashed up onto the inclined top of said housing, flows downinto the said upper passage to said bearing and back to said depressionthrough said lower passage.

20. In a centrifugal grinding mill having a grinding chamber, grindingrolls movable in said chamber, means forfmoving said rolls comprisin abevel pinion and a shaft on which sai pinion is mounted, an overheadbeam formed with-a single recess extending along its length, said recessbeing formed with a depression adapted to contain oil in which saidpinion dips, bearings for said shaft in said recess on opposite sides ofsaid depression, and means whereby oil splashed up by the rotation ofsaid pinion lubricatesV said bearings and is returned to saiddepression.'

' 2l. In a centrifugal grinding millnhaving a grinding chamber, grindingrolls movable in said chamber, means for moving said rolls comprising abevel pinion and a sha-ft on which said pinion is mounted, an overhead`beam formed with a single recess extending 22. In a centrifugalgrinding mill, a ro-l tary support, depending spindles mountedeccentrically on said support, each of said spindlesA being formed witha supporting shoulder, an annular member rotatably mounted on saidsupporting shoulder and formed at its lower end and at said shoulderwith an outwardly extending flange, a member rigidly secured to saidan'ge and enclosing the lower end of said spindle, side roller bearingsbetween said spindle and last named member and between said shoulder andannular member, and a grinding roll rigidl 'and removably secured tosaid last name member.

23. In a centrifugal grinding mill, a rotary support, spindles hungeccentrically from said support, each of said spindles being formed witha supporting shoulder,'an annular member rotatably mounted on saidsupporting shoulder, and formed at its lower end and at said shoulderwith an outwardly extending' flange, a roll-supporting member rigidlysecured to said flange, said annular and roll-supporting membersenclosing the lower end of said spindle, said roller bearings betweensaid spindle and roll-supporting member below said shoulder and betweensaid spindle and annular member above said shoulder, and a grinding rollrigidly and removably secured to said roll-supporting member.

24. In a centrifugal grinding mill, a grinding roll formed with atapered opening, a rotary support therefor formed with a tapered portionadapted to be received in the tapered .o eninor of said indino rollsecurin means e z: a g

on the end of said tapered portion, jack screws passing through saidmeans and adapted to engage said grinding roll toforce the same ontothe-tapered portion of said rotary support.

25. In a centrifugal grinding mill, a grind- A' which said inion ismounted, an overhead beam formed with a single recess extendin along itslength, said recess being form with a depression adapted to contain'oilin which said pinion dips, bearin for said shaft in said recess onopposite sides of said depression, and means whereby oil is splashed upby the rotation of said pinion, lubricates said bearings and is returnedto said depression, said means comprising members located above saidshaft for directing oil s lashed up by the pinion, laterally toward saidbearings.

CHARLES E. NEEDHAM.

